In the semiconductor field, each set of wafers fabricated is typically performance tested, before they are diced into individual integrated circuits. FIGS. 1–4 show equipment that is used in this testing. Although these figures show an embodiment of the invention they also show some features that are shared with prior art systems. These features are referenced in this section to help explain the context of the invention.
To perform wafer testing a piece of equipment known as a probe station 10 has a head plate 12 (FIG. 3) that defines an original head plate aperture 14. The aperture supports a circular device known as a probe card dish 16, which in turn supports the probe card 17. A separate piece of equipment, known as a tester 18 having docking units 20, is lowered into mating position with respect to the probe station, the probe card dish and the probe card. Sometimes probe station 10 includes an obstacle, such as a wafer loader cover 19, that is too close to the original head plate aperture 14 to permit the docking of a particular tester 18.
Generally, a number of guides and associated docking equipment pieces are needed to successfully dock a tester to a probe station, a probe card dish and the wafer that the probe card dish supports. Probe stations are generally sold to semiconductor manufacturing facilities with this docking equipment already installed. Accordingly, when a new tester is purchased it is typically necessary to purchase a new probe station fitted with docking equipment to facilitate docking with the new tester. Unfortunately, the docking equipment, which is typically installed by the probe station vendor or a secondary source, generally permits docking to a single make of tester. The installation of docking equipment to permit the use of a different tester with the probe station is referred to in the industry as “hardware swap-out” and results in extensive use of technician time and equipment down time.
It is known to machine a single prober to accept a single tooling plate that permits docking to a desired tester. There appears, however, not to have been an effort in the prior art to produce a set of standardized tooling plates that could each be used on any one of a set of differing probe stations. As a result, only very limited flexibility was gained by this method.
Another issue facing semiconductor manufacturers is the lack of uniformity of head plate apertures, between the various commercial lines of probe stations. The unfortunate result is that there is currently no known technique for mating a probe station having a first head plate aperture size with a tester designed to mate with a prober having a second head plate aperture size.